Drive assembly, drive component and drug delivery device

ABSTRACT

A drive assembly ( 70 ) for a drug delivery device ( 1 ) comprises a rotation member ( 21 ) being configured to be rotated in a first direction ( 44 ) during setting of a dose of a drug and to be rotated in a second direction ( 47 ) during delivery of the dose, a drive component ( 20 ) being configured to follow rotational movement of the rotation member ( 21 ) in the second direction ( 47 ) during delivery of the dose and a stop member ( 26 ) being configured to prevent rotational movement of the drive component ( 20 ) in the first direction ( 44 ). The drive component ( 20 ) comprises a first drive part ( 71 ) and a second drive part ( 72 ), coupled to each other such that relative rotational movement of the first and second drive parts ( 71, 72 ) is prevented and relative axial movement is permitted.

The present disclosure relates to a drive assembly for a drug deliverydevice and a drug delivery device incorporating such a drive assembly.

A drug delivery device may comprise a cartridge containing a drug. Forexpelling a dose of the drug from the cartridge, a piston within thecartridge may be displaced in a distal direction by a piston rod. A drugdelivery device is described in US 2007/0123829 A1, for example.

It is an object of the present invention to provide a drive assembly, adrive component of a drive assembly and a drug delivery device, whereinan administration of a drug is improved.

According to one aspect, a drive assembly for a drug delivery device isprovided. The drive assembly comprises a housing having a proximal endand a distal end. Furthermore, the drive assembly comprises a rotationmember being configured to be rotated in a first direction with respectto the housing during setting of a dose of a drug and to be rotated in asecond direction with respect to the housing during delivery of thedose, the second direction being opposite to the first direction.Moreover, the drive assembly comprises a drive component beingconfigured to follow rotational movement of the rotation member in thesecond direction during delivery of the dose and a stop member beingconfigured to prevent rotational movement of the drive component in thefirst direction with respect to the housing and to permit rotationalmovement of the drive component in the second direction with respect tothe housing. The drive component comprises a first drive part and asecond drive part, coupled to each other such that relative rotationalmovement of the first and second drive parts is prevented and relativeaxial movement of the first and second drive parts is permitted.Preferably, the first drive part is configured for engagement with therotation member and the second drive part is configured for engagementwith the stop member.

In this context, the term “housing” shall mean any exterior housing,interior housing or a part fixed to an exterior or interior housing suchthat a relative movement between this part and the exterior or interiorhousing is prevented. The housing may be designed to enable the safe,correct, and comfortable handling of the drug delivery device or any ofits mechanisms. It may be designed to house, fix, protect, guide, and/orengage with any of the inner components of the drug delivery device,e.g., the drive assembly, cartridge, piston, piston rod. The housing maybe unitary or a multipart component of tubular or non-tubular shape.

The term “distal end” designates that end of a drug delivery device or acomponent thereof which is or is to be arranged closest to a dispensingend of the drug delivery device. The term “proximal end” designates thatend of the device or a component thereof which is or is to be arrangedfurthest away from the dispensing end of the device. Accordingly, theterm “distal direction” designates the direction from the proximal endtowards the distal end and the term “proximal direction” designates thedirection from the distal end towards the proximal end.

The drug delivery device may be an injection device. The drug deliverydevice may be a pen-type device, in particular a pen-type injector. Thedevice may be a disposable or a re-usable device. The device may be afixed-dose device, where a user is disabled from selecting the size of adose. Here, the absolute sizes of the doses to be dispensed arepredetermined by the design of the device. The device may be configuredsuch that each dose to be dispensed has the same size or such that thesizes of the doses vary. Alternatively, the device may be avariable-dose device, wherein the absolute size of a dose to bedispensed can be selected by a user. In particular, the user can choosebetween different dose sizes. The drug delivery device may be amanually, in particular a non-electrically, driven device.

Mechanical interaction of the stop member and the drive component, inparticular of the stop member and the second drive part, may preventrotational movement of the drive component with respect to the housingin the first direction and, in particular, with respect to the stopmember during setting of the dose. Thus, rotation of the drive componentduring dose setting can be avoided. As examples, such a mechanicalinteraction may comprise interlocking, engagement and/or abutment,during rotation of the rotation member in the first direction. As anexample, the second drive part may comprise a toothing for engagementwith the stop member.

The drive assembly may comprise a piston rod being configured to bedisplaced in the distal direction for delivering a dose of a drug andbeing configured such that rotational movement of the drive component inthe second direction is at least partially converted into movement ofthe piston rod in the distal direction with respect to the housing.

The term “piston rod” shall preferably mean a component adapted tooperate through/within the housing, which may be designed to transferaxial movement through/within the drug delivery device, preferably fromthe drive component to the piston, for example for the purpose ofdischarging/dispensing an injectable product.

Said piston rod may be flexible or not. It may be a simple rod, alead-screw, a rack and pinion system, a worm gear system, or the like.The term “piston rod” shall further mean a component having a circularor non-circular cross-section. It may be made of any suitable materialknown by a person skilled in the art and may be of unitary or multipartconstruction.

The drive component may be coupled to the piston rod so as to at leastpartially convert the drive components rotational movement in the seconddirection into distal movement of the piston rod with respect to thehousing. The drive component may be engaged with the piston rod suchthat relative axial movement between the piston rod and the drivecomponent is allowed and relative rotational movement is prevented. Inparticular, the drive component, for example at least one of the firstand second drive parts, may be engaged with the piston rod. The drivecomponent may be in splined engagement with the piston rod.

The drive component may also be coupled to the piston rod such that amovement of the drive component in the first direction may be at leastpartially converted into a movement of the piston rod in the proximaldirection with respect to the housing. Accordingly, the risk of thepiston rod being moved in the proximal direction during dose setting canbe reduced by preventing rotational movement of the drive component inthe first direction during setting of the dose due to provision of thestop member. Unintentional proximal movement of the piston rod mayresult in decreased dose accuracy. Consequently, dose accuracy may beimproved by preventing rotation of the drive component with respect tothe housing during dose setting.

According to a preferred embodiment, the drive component and therotation member are rotatable around a common rotation axis. The pistonrod may be displaced in the distal direction with respect to the housingalong the rotation axis. The rotation axis may run along the piston rodand, in particular, along a main direction of extent of the piston rod.

The drive component, in particular the first drive part and the seconddrive part, may be arranged between the stop member and the rotationmember.

The rotational movement of the drive component in the second directionmay be at least partially converted into rotational movement of thepiston rod with respect to the housing, in particular rotationalmovement in the same direction and/or by the same angle, and movement ofthe piston rod with respect to the housing in the distal direction. Thepiston rod may be threadedly coupled to the housing, in particularthreadedly engaged with the housing, for this purpose.

According to another embodiment, the rotational movement of the drivecomponent is converted into pure linear movement of the piston rod inthe distal direction. Accordingly, the piston rod may be moved in thedistal direction without rotating with respect to the housing. It isparticularly suitable for the drive component to comprise gear teeth forengaging the piston rod, for this purpose.

The drive assembly may comprise a dose member. The dose member ispreferably movable with respect to the housing, for example duringsetting and delivery of a dose.

The dose member may be movable in the proximal direction with respect tothe housing for setting the dose. The dose member may be movable in thedistal direction with respect to the housing for delivering the setdose. Movement of the dose member with respect to the housing may beconverted into rotational movement of the rotation member with respectto the housing. Movement of the dose member for setting the dose may beconverted into rotational movement of the rotation member with respectto the housing in the first direction. Movement of the dose member fordelivering the set dose may be converted into rotational movement of therotation member with respect to the housing in the second direction. Thedose member may be secured against rotational movement with respect tothe housing. The dose member may be splined to the housing, for example.The dose member may be movable with respect to the rotation member.Movement of the dose member with respect to the rotation member may beconverted into rotational movement of the rotation member.

The dose member and the rotation member may be engaged, preferablythreadedly engaged. As an example, rotational movement of the rotationmember may be achieved by a threaded engagement which may convert linearmovement of the dose member into rotational movement of the rotationmember with respect to the housing.

According to a preferred embodiment, the first drive part, preferablypermanently, abuts and/or engages the rotation member during rotationalmovement of the rotation member for setting and delivery of the dose.The second drive part may, preferably permanently, abut and/or engagethe stop member during rotational movement of the rotation member forsetting and delivery of the dose. In a preferred embodiment, the firstdrive part permanently abuts the rotation member and the second drivepart permanently abuts the stop member.

According to a preferred embodiment, the drive component comprises abiasing member for providing a force on at least one of the first andsecond drive parts for keeping at least one of the first and seconddrive parts in abutment with at least one of the rotation member and thestop member. Preferably, the biasing member provides a force on both thefirst and second drive part to keep the first drive part in abutmentwith the rotation member and the second drive part in abutment with thestop member. As an example, the biasing member may be a spring member.Preferably, the biasing member abuts at least one of the first andsecond drive parts for providing a force on the respective drive part.

Preferably, thereby, the first drive part is held in permanent abutmentwith the rotation member and the second drive part is held in permanentabutment with the stop member during setting and delivery of the dose,in particular during rotational movement of the rotation member in thefirst direction and in the second direction.

The biasing member may be located between the first and second drivepart. Here, at least a part of the first drive part is located at oneend of the biasing member, for example its proximal end, and at least apart of the second drive part is located at the opposite end of thebiasing member, for example its distal end. The biasing member may beintegrated into the drive component such that the drive componentcomprising the first and second drive parts and the biasing member isprovided as a pre-assembled component fittable into other parts of thedrive assembly. Thereby, the number of separate components of the driveassembly may be reduced and the assembly process of the drive assemblymay be improved.

The biasing member may abut, preferably permanently abut, at least oneof the first and second drive parts. Preferably, the biasing memberabuts both the first and second drive parts. Preferably, the biasingmember may be configured such that it follows rotational movements ofthe first and second drive parts.

Preferably, the biasing member forces the first and second drive partsapart in opposite axial directions. Thereby, the first drive part may beforced onto the rotation member and the second drive part may be forcedonto the stop member.

According to an embodiment, the stop member is secured againstrotational movement with respect to the housing. According to apreferred embodiment, the stop member is secured against both axial androtational movement with respect to the housing.

As examples, the stop member may be permanently fixed to the housing,for example may be designed as an insert fixed to the inner side of thehousing, or may be an integral part of the housing.

In a preferred embodiment, the drive component and the rotation memberare coupled, preferably permanently coupled, to one another by auni-directional friction clutch mechanism. Preferably, here, the firstdrive part and the rotation member are coupled by the uni-directionalfriction clutch mechanism. This friction clutch mechanism may beconfigured to permit relative rotational movement between rotationmember and drive component during movement of the rotation member forsetting of the dose and to prevent relative rotational movement ofrotation member and drive component during movement of the rotationmember for delivery of the dose.

In a preferred embodiment, the drive component and the stop member arecoupled, preferably permanently, to one another by a uni-directionalfriction clutch mechanism. Preferably, here, the second drive part andthe stop member are coupled by the uni-directional friction clutchmechanism. This friction clutch mechanism may be configured to preventrelative rotational movement between the stop member and the drivecomponent during movement of the rotation member for setting of the doseand to permit relative rotational movement of the stop member and thedrive component during movement of the rotation member for delivery ofthe dose.

According to a preferred embodiment, at least one of the drivecomponent, the stop member, the rotation member and the dose member maybe formed as or may comprise a sleeve. A rod, for example the piston rodor an axis rod which defines the rotation axis may extend through oneof, more of or all of drive sleeve, stop sleeve, rotation sleeve anddose sleeve.

Preferably, at least one of the first and second drive parts comprises asleeve. The piston rod may extend through the sleeve. In a preferredembodiment, both drive parts comprise a sleeve. One of the sleeves mayat least partially enclose the other sleeve.

The sleeves may be slidably coupled to each other. As an example, thesleeve of the first drive part may partially enclose the sleeve of thesecond drive part.

The drive component may comprise retaining means to limit the axialseparation of the first and second drive parts. The retaining means maybe configured such that a complete separation of the first and seconddrive parts may be prevented in a state where the drive component is notassembled with other parts of the drive assembly.

As an example, the retaining means may be arranged at one of or both thefirst and second drive parts. The retaining means may comprise a firststop face on one of the drive parts arranged for abutment with a secondstop face on the other drive part. The stop faces may be designed suchthat at a defined axial separation of the drive parts the stop facesabut and thereby prevent further separation of the drive parts.

According to a further aspect, there is provided a drive component foruse in a drive assembly as described above, the drive component beingprovided as a pre-assembled component for assembly with the rotationmember, the stop member and the housing for building the drive assembly.The drive component comprises a first drive part and a second drive partcoupled to each other such that relative rotational movement of thefirst and second drive parts is prevented and relative axial movement ispermitted. The first drive part may comprise first engagement means,e.g. a toothing. The first engagement means may be configured forestablishing a uni-directional friction clutch mechanism which isadapted and arranged to prevent rotational movement of the first drivepart in a first direction and to permit rotational movement of the firstdrive part in a second direction with respect to a mating firstengagement means, e.g. a mating toothing. The second drive part maycomprise second engagement means, e.g. a toothing, for establishing auni-directional friction clutch mechanism which is adapted and arrangedto prevent rotational movement of the second drive part in the firstdirection and to permit rotational movement of the second drive part inthe second direction with respect to a second mating engagement means,e.g. a further toothing.

The first drive part is configured for engagement with the rotationmember of the drive assembly and the second drive part is configured forengagement with the stop member of the drive assembly.

In particular, the drive component may be configured such that in astate before the drive component is assembled with further parts of thedrive assembly, a complete separation of any of its parts from the drivecomponent, for example a falling away of a part, is prevented. For thisaim, the drive component may comprise retaining means, for exampleretaining means as described above. The retaining means may prevent acomplete separation of the first and second drive parts.

According to an embodiment, the first and the second engagement meansare configured to face in opposite directions with respect to oneanother.

The first engagement means may comprise a first toothing comprising aplurality of teeth. The second engagement means may comprise a secondtoothing comprising a plurality of teeth. The first toothing may beoppositely arranged compared to the second toothing.

The first mating engagement means may comprise a first mating toothingcomprising a plurality of teeth. The second mating engagement means maycomprise a second mating toothing comprising a plurality of teeth. Thefirst mating toothing may be oppositely arranged compared to the secondmating toothing.

According to an embodiment, the drive component comprises a biasingmember, e.g. a compression spring. The biasing member may be adapted andarranged to provide a force which tends to force the first and seconddrive parts away from each other in opposite axial directions.

The biasing member may be configured such that the first drive part isheld in engagement with the rotation member during a delivery operation.The biasing member may be configured such that the second drive part isheld in engagement with the stop member during a delivery operation.

In a preferred embodiment, the drive component comprises a biasingmember as described above, which is part of the pre-assembled component.The biasing member may provide a force on at least one of the first andsecond drive parts. The biasing member may force the first and seconddrive parts apart in opposite axial directions.

Preferably, the drive component is configured such that a completeseparation, for example a falling away, of the biasing member from atleast one of the first and second drive parts is prevented. As anexample, the biasing member may be located between the first and seconddrive parts and may be held in place by the first and second driveparts. Additionally or alternatively, the drive component may comprisefurther retaining means for preventing a complete separation, forexample a falling away, of the biasing member.

Features described above and below in connection with the drive assemblyand the drive component may also be applied for the corresponding drivecomponent which is provided as a pre-assembled component.

As an example, at least one of the first and second drive parts maycomprise a toothing for engagement with at least one of the stop memberand the rotation member. Preferably, both the first and second driveparts comprise a toothing. As an example, the first drive part maycomprise a toothing at its proximal end and the second drive part maycomprise a toothing at its distal end.

According to a further aspect, a drug delivery device is provided, thedrug delivery device comprising at least one of the drive assembly andthe drive component as described above. The device may comprise meansfor attaching a drug reservoir. The drug reservoir may be permanently orreleasably attached to the housing of the device.

The term “drug” as used herein, preferably means a pharmaceuticalformulation containing at least one pharmaceutically active compound,

wherein in one embodiment the pharmaceutically active compound has amolecular weight up to 1500 Da and/or is a peptide, a proteine, apolysaccharide, a vaccine, a DNA, a RNA, an enzyme, an antibody, ahormone or an oligonucleotide, or a mixture of the above-mentionedpharmaceutically active compound,

wherein in a further embodiment the pharmaceutically active compound isuseful for the treatment and/or prophylaxis of diabetes mellitus orcomplications associated with diabetes mellitus such as diabeticretinopathy, thromboembolism disorders such as deep vein or pulmonarythromboembolism, acute coronary syndrome (ACS), angina, myocardialinfarction, cancer, macular degeneration, inflammation, hay fever,atherosclerosis and/or rheumatoid arthritis,

wherein in a further embodiment the pharmaceutically active compoundcomprises at least one peptide for the treatment and/or prophylaxis ofdiabetes mellitus or complications associated with diabetes mellitussuch as diabetic retinopathy,

wherein in a further embodiment the pharmaceutically active compoundcomprises at least one human insulin or a human insulin analogue orderivative, glucagon-like peptide (GLP-1) or an analogue or derivativethereof, or exedin-3 or exedin-4 or an analogue or derivative ofexedin-3 or exedin-4.

Insulin analogues are for example Gly(A21), Arg(B31), Arg(B32) humaninsulin; Lys(B3), Glu(B29) human insulin; Lys(B28), Pro(B29) humaninsulin; Asp(B28) human insulin; human insulin, wherein proline inposition B28 is replaced by Asp, Lys, Leu, Val or Ala and wherein inposition B29 Lys may be replaced by Pro; Ala(B26) human insulin;Des(B28-B30) human insulin; Des(B27) human insulin and Des(B30) humaninsulin.

Insulin derivates are for example B29-N-myristoyl-des(B30) humaninsulin; B29-N-palmitoyl-des(B30) human insulin; B29-N-myristoyl humaninsulin; B29-N-palmitoyl human insulin; B28-N-myristoyl LysB28ProB29human insulin; B28-N-palmitoyl-LysB28ProB29 human insulin;B30-N-myristoyl-ThrB29LysB30 human insulin; B30-N-palmitoyl-ThrB29LysB30human insulin; B29-N—(N-palmitoyl-Y-glutamyl)-des(B30) human insulin;B29-N—(N-lithocholyl-Y-glutamyl)-des(B30) human insulin;B29-N-(ω-carboxyheptadecanoyl)-des(B30) human insulin andB29-N-(ω-carboxyheptadecanoyl) human insulin.

Exendin-4 for example means Exendin-4(1-39), a peptide of the sequenceH-His-Gly-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH2.

Exendin-4 derivatives are for example selected from the following listof compounds:

H-(Lys)4-des Pro36, des Pro37 Exendin-4(1-39)-NH2,

H-(Lys)5-des Pro36, des Pro37 Exendin-4(1-39)-NH2,

des Pro36 [Asp28] Exendin-4(1-39),

des Pro36 [IsoAsp28] Exendin-4(1-39),

des Pro36 [Met(O)14, Asp28] Exendin-4(1-39),

des Pro36 [Met(O)14, IsoAsp28] Exendin-4(1-39),

des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39),

des Pro36 [Trp(O2)25, IsoAsp28] Exendin-4(1-39),

des Pro36 [Met(O)14 Trp(O2)25, Asp28] Exendin-4(1-39),

des Pro36 [Met(O)14 Trp(O2)25, IsoAsp28] Exendin-4(1-39); or

des Pro36 [Asp28] Exendin-4(1-39),

des Pro36 [IsoAsp28] Exendin-4(1-39),

des Pro36 [Met(O)14, Asp28] Exendin-4(1-39),

des Pro36 [Met(O)14, IsoAsp28] Exendin-4(1-39),

des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39),

des Pro36 [Trp(O2)25, IsoAsp28] Exendin-4(1-39),

des Pro36 [Met(O)14 Trp(O2)25, Asp28] Exendin-4(1-39),

des Pro36 [Met(O)14 Trp(O2)25, IsoAsp28] Exendin-4(1-39),

wherein the group -Lys6-NH2 may be bound to the C-terminus of theExendin-4 derivative;

or an Exendin-4 derivative of the sequence

H-(Lys)6-des Pro36 [Asp28] Exendin-4(1-39)-Lys6-NH2,

des Asp28 Pro36, Pro37, Pro38Exendin-4(1-39)-NH2,

H-(Lys)6-des Pro36, Pro38 [Asp28] Exendin-4(1-39)-NH2,

H-Asn-(Glu)5des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-NH2,

des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39)-Lys6-NH2,

H-des Asp28 Pro36, Pro37, Pro38 [Trp(O2)25] Exendin-4(1-39)-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1-39)-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28]Exendin-4(1-39)-NH2,

des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28]Exendin-4(1-39)-(Lys)6-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28]Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36 [Met(O)14, Asp28] Exendin-4(1-39)-Lys6-NH2,

des Met(O)14 Asp28 Pro36, Pro37, Pro38 Exendin-4(1-39)-NH2,

H-(Lys)6-desPro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Asp28]Exendin-4(1-39)-NH2,

des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Asp28]Exendin-4(1-39)-(Lys)6-NH2,

H-Asn-(Glu)5 des Pro36, Pro37, Pro38 [Met(O)14, Asp28]Exendin-4(1-39)-(Lys)6-NH2,

H-Lys6-des Pro36 [Met(O)14, Trp(O2)25, Asp28] Exendin-4(1-39)-Lys6-NH2,

H-des Asp28 Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25]Exendin-4(1-39)-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28]Exendin-4(1-39)-NH2,

des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28]Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28]Exendin-4(S1-39)-(Lys)6-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28]Exendin-4(1-39)-(Lys)6-NH2;

or a pharmaceutically acceptable salt or solvate of any one of theafore-mentioned Exedin-4 derivative.

Hormones are for example hypophysis hormones or hypothalamus hormones orregulatory active peptides and their antagonists as listed in RoteListe, ed. 2008, Chapter 50, such as Gonadotropine (Follitropin,Lutropin, Choriongonadotropin, Menotropin), Somatropine (Somatropin),Desmopressin, Terlipressin, Gonadorelin, Triptorelin, Leuprorelin,Buserelin, Nafarelin, Goserelin.

A polysaccharide is for example a glucosaminoglycane, a hyaluronic acid,a heparin, a low molecular weight heparin or an ultra low molecularweight heparin or a derivative thereof, or a sulphated, e.g. apoly-sulphated form of the above-mentioned polysaccharides, and/or apharmaceutically acceptable salt thereof. An example of apharmaceutically acceptable salt of a poly-sulphated low molecularweight heparin is enoxaparin sodium.

Pharmaceutically acceptable salts are for example acid addition saltsand basic salts. Acid addition salts are e.g. HCl or HBr salts. Basicsalts are e.g. salts having a cation selected from alkali or alkaline,e.g. Na+, or K+, or Ca2+, or an ammonium ion N+(R1)(R2)(R3)(R4), whereinR1 to R4 independently of each other mean: hydrogen, an optionallysubstituted C1-C6-alkyl group, an optionally substituted C2-C6-alkenylgroup, an optionally substituted C6-C10-aryl group, or an optionallysubstituted C6-C10-heteroaryl group. Further examples ofpharmaceutically acceptable salts are described in “Remington'sPharmaceutical Sciences” 17. ed. Alfonso R. Gennaro (Ed.), MarkPublishing Company, Easton, Pa., U.S.A., 1985 and in Encyclopedia ofPharmaceutical Technology.

Pharmaceutically acceptable solvates are for example hydrates.

Further features, refinements and expediencies become apparent from thefollowing description of the exemplary embodiments in connection withthe figures.

FIG. 1 schematically shows a partly sectional side view of an exemplaryembodiment of a drug delivery device.

FIG. 2 schematically shows a perspective sectional view of a driveassembly with schematically indicated movements of elements duringsetting of a dose.

FIG. 3 schematically shows a more detailed side view of a part of FIG.2.

FIG. 4 schematically shows a perspective sectional view of a driveassembly with schematically indicated movements of elements duringdelivering a dose.

FIG. 5 schematically shows a more detailed side view of a part of FIG.4.

FIG. 6 schematically shows a more detailed view of a part of FIGS. 2 and4.

Like elements, elements of the same kind and identically acting elementsare provided with the same reference numerals in the figures.

FIG. 1 shows a drug delivery device 1 having a distal end 7 and aproximal end 8. The device 1 comprises a cartridge part 2 and a drivepart 3. The cartridge part 2 comprises a drug reservoir in form of acartridge 4 retaining a drug 5, preferably a liquid drug. The cartridge4 preferably comprises a plurality of doses of the drug 5. The drug 5may comprise insulin, heparin, or growth hormones, for example. Thecartridge 4 has an outlet 6 at its distal end. The drug 5 can bedispensed from the cartridge through the outlet 6.

The device 1 may be a pen-type device, in particular a pen-typeinjector. The device 1 may be a disposable or a reusable device. Thedevice 1 may be a fixed-dose device, wherein a user can not choosebetween different dose sizes, or a variable-dose device, wherein a usercan choose between different dose sizes. The device 1 may be aneedle-based or a needle free device. The device 1 may be an injectiondevice.

The outlet 6 may be covered by a membrane 9, which protects the drug 5against external influences during storage of the cartridge. For drugdelivery, membrane 9 may be opened, e.g. pierced. For example, membrane9 may be pierced by a needle unit (not explicitly shown). The needleunit may be attached, for example releasably attached, to the distal endof the cartridge part 2. The needle unit may provide for fluidcommunication from the inside of the cartridge 4 to the outside of thecartridge through outlet 6.

A piston 10 is retained within the cartridge 4. The piston 10 is movablewith respect to the cartridge 4. The piston 10 may seal the drug 5within the cartridge 4. The piston 10 expediently seals the interior ofthe cartridge 4 proximally. Movement of the piston 10 with respect tothe cartridge 4 in the distal direction causes the drug 5 to bedispensed from the cartridge 4 through outlet 6 during operation of thedevice 1.

The cartridge part 2 furthermore comprises a cartridge retaining member11, wherein the cartridge 4 is retained. The cartridge retaining member11 may at least partially house the cartridge 4. The cartridge retainingmember 11 may be provided with a fixing member (not explicitly shown)for attaching the cartridge part 2 to the drive part 3.

The cartridge part 2 and the drive part 3 are secured to one another,preferably releasably secured. A cartridge part 2 which is releasablysecured to the drive part 3 may be detached from the drive part 3, forexample in order to allow for replacing the cartridge 4. As an example,if all the doses of the drug retained in a cartridge 4 have beendispensed, the cartridge 4 may be removed and a new cartridge may besecured to the drive part 3. The cartridge retaining member 11 may bereleasably secured to the drive part 3 via a thread, for example.Alternatively, the cartridge retaining member 11 may be dispensed with.It is particularly expedient, in this case, to apply a robust cartridge4 and to attach the cartridge directly to the drive part 3.

The drive part 3 comprises a housing 13 which may be part of a driveassembly. A proximal end side 14 of the cartridge part 2 is secured tothe drive part 3 at a distal end side 15 of the housing 13, for examplevia a threaded connection. Housing 13, cartridge 4 and/or cartridgeretaining member 11 may have a tubular shape.

The drive part 3 is configured for transferring force, preferablyuser-exerted force, particularly preferably manually exerted force, tothe piston 10 for displacing the piston 10 with respect to the cartridge4 in the distal direction. A dose of drug 5 may be dispensed from thecartridge 4 in this way. The size of the delivered dose 5 may bedetermined by the distance by which the piston 10 is displaced withrespect to the cartridge 4 in the distal direction.

The drive part 3 comprises a drive assembly comprising a piston rod 12.The piston rod 12 is configured for transferring force to the piston 10,thereby displacing the piston in the distal direction with respect tothe cartridge 4. A distal end face of the piston rod 12 is arranged toabut a proximal end face of the piston 10. A bearing member (notexplicitly shown) may be arranged to advance the piston 10, preferablyto abut the proximal end face of the piston 10. The bearing member maybe located between piston 10 and piston rod 12. The bearing member maybe secured to the piston rod 12 or a separate member. If the piston rod12 is configured to be rotated during operation of the device 1, forexample during dose delivery, it is particularly expedient to providefor a bearing member. The bearing member may be displaced together withthe rotating piston rod 12 with respect to the housing 13. The pistonrod 12 may be rotatable with respect to the bearing member. In this way,the risk that the rotating piston rod 12 drills into the piston 10 andthereby damages the piston 10 is reduced. Accordingly, while the pistonrod 12 rotates and is displaced with respect to the housing 13, thebearing member is preferably only displaced, i.e. does not rotate. Thepiston rod 12 may be bounded by the bearing member.

The drive part 3 comprises a dose part 16. The dose part 16 is movablewith respect to the housing 13. The dose part 16 may be movable in theproximal direction with respect to the housing 13 for setting a dose ofthe drug 5 which is to be delivered and may be movable in the distaldirection with respect to the housing 13 for delivery of the set dose.The dose part 16 is preferably coupled to the housing 13. The dose part16 may be secured against rotational movement with respect to thehousing 13. The dose part 16 may be displaced from a distal end positionto a proximal end position with respect to the housing 13 for setting adose and from the proximal end position to the distal end position fordelivering the dose (not explicitly shown). The distance by which thedose part 16 is displaced with respect to the housing 13 during settingof the dose may determine a size of the dose. The proximal end positionand the distal end position may be determined by a respective stopfeature which may limit the proximal or distal travel of the dose part16 with respect to the housing. The dose part 16 may comprise a doseknob, which may be gripped by a user. The dose knob 41 may be arrangedand connected to the dose part 16 at the proximal end of the dose part16. Dose knob 41 and dose part 16 may be a unitary component.

The device 1 may be a manually, in particular non-electrically, drivendevice. The user-applied force which causes the dose part 16 to be movedwith respect to the housing 13 in the distal direction for delivering adose may be transferred to the piston rod 12 by other parts of the driveassembly. The drive assembly is preferably configured such that amovement of the piston rod 12 with respect to the housing 13 isprevented when the dose part 16 is moved for setting a dose, for examplein the proximal direction with respect to the housing 13.

Embodiments of a drive assembly which are suitable to be provided in thedrug delivery device 1 as described above are described in more detailin the following.

FIG. 2 shows a perspective sectional view of a drive assembly 70 of thedrive part 3 of the device 1. FIG. 6 shows a more detailed view of apart of FIG. 2. FIG. 3 shows a part of the drive assembly 70 of FIG. 2.

The drive assembly 70 comprises a housing part 17. The housing part 17has a proximal end 18 and a distal end 19. The housing part 17 may be anouter housing 13 of the drive part 3 shown in FIG. 1, a part thereof oran insert within housing 13. The insert is secured against rotationaland axial movement with respect to housing 13. The housing part 17 maybe an insert sleeve, for example. The insert sleeve may be snap-fittedor glued to housing 13, for example. The housing part 17 has a tubularshape. Housing part 17 may comprise outer fixing elements (notexplicitly shown), for example snap-fit elements, for fixing housingpart 17 to housing 13.

The piston rod 12 is retained in the housing 13, in particular withinthe housing part 17. The piston rod 12 is driven in the distal directionwith respect to the housing part 17 during dose delivery.

The drive assembly 70 furthermore comprises a drive component 20retained within the housing part 17. The drive component 20 isconfigured to transfer force, preferably torque, to the piston rod 12.The transferred force causes the piston rod 12 to be displaced in thedistal direction with respect to the housing part 17 for dose delivery.

The drive component 20 comprises a first drive part 71 and a seconddrive part 72, which are coupled to each other such that relativerotational movements with respect to each other are disabled andrelative axial movements with respect to each other are allowed. As anexample, the first drive part 71 may be in splined engagement with thesecond drive part 72. Here, one of the drive parts 71, 72 may have aguide slot 77 running in an axial direction, wherein an engagementfeature 79 of the other drive part 71, 72, for example a guide lug maybe guided (see FIG. 6).

Each of the first and the second drive parts 71, 72 comprises a sleeve,wherein the sleeve of the second drive part 72 is partially insertedinto the sleeve of the first drive part 71. Both the first and seconddrive parts 71, 72 are axially displaceable relative to the housing part17. The axial movement of the first and second drive parts 71, 72relative to each other and relative to the housing 13 may compensate forplay between components of the drive assembly 70 during operation.

The drive component 20 comprises a biasing member 73 in form of ahelical spring member, in particular a compression spring. The biasingmember 73 is biased during drug delivery operations of the driveassembly 70. The biasing member 73 provides for a force forcing thefirst and second drive parts 71, 72 apart from each other in oppositeaxial directions.

The biasing member 73 is located between a flange 74 at the distal endof the second drive part 72 and a distal end face 75 of the sleeve ofthe first drive part 71. The biasing member 73 is wound around thesleeve of the second drive part 72 and thus partially encloses thesleeve. The biasing member 73 abuts the flange 74 of the second drivepart 72 and abuts the distal end face 75 of the sleeve of the firstdrive part 71 and thereby provides a separating force on the first andsecond drive parts 71, 72.

In further embodiments, the biasing member 73 may be coupled in adifferent way to the first and second drive parts 71, 72 for providing aseparating force on the first and second drive parts 71, 72. As anexample, the biasing member 73 may be arranged inside at least one ofthe first and second drive parts 71, 72. In this case, the biasingmember 73 may abut a distal internal end face of the second drive part72.

The drive component 20 may comprise retaining means 76 (see FIG. 6)limiting the relative axial separation of the first and second driveparts 71, 72. In particular, the first and second drive parts 71, 72 maycomprise clip features or other retention features. As an example, astop face 78 may be located at the distal end of a guide slot 77 in thefirst drive part 71 wherein an engagement feature 79 of the second drivepart 72 is guided. At an axial separation of the first and second driveparts 71, 72 where the engagement feature 79 abuts the stop face 78, afurther relative separation of the first and second drive parts 71, 72may be prevented.

In a preferred embodiment, the drive component 20 is configured suchthat it is provided as a pre-assembled component before it is fittedinto other parts of the drive assembly 70. Preferably, the drivecomponent 20 comprises the biasing member 73, the first drive part 71and the second drive part 72 coupled to each other such that disassemblyfrom each other is prevented.

The drive component 20, comprising the first and second drive parts 71,72 and the biasing member 73, is rotatable with respect to the housingpart 17. The drive component 20, for example at least one of the firstand second drive parts 71, 72, engages the piston rod 12. Thereby,rotational movement of the drive component 20, for example rotationalmovement in a second direction, is converted into distal movement of thepiston rod 12 with respect to the housing part 17. This is explained inmore detail below.

The drive assembly 70 furthermore comprises a rotation member 21. Therotation member 21 is rotatable with respect to the housing part 17 in afirst direction, in particular for setting a dose of the drug, and in asecond direction, in particular for delivering the set dose. The seconddirection is opposite to the first direction. The first direction may becounter-clockwise and the second direction may be clockwise as seen fromthe proximal end of the device 1, for example.

The first and second drive parts 71, 72 of the drive component 20, therotation member 21 and the piston rod 12 are configured to be rotatableabout a common rotation axis. The rotation axis extends through thedrive component 20, the rotation member 21 and the piston rod 12. Therotation axis is the main longitudinal axis of the piston rod 12. Therotation axis runs between the proximal end and the distal end of thehousing part 17.

The rotation member 21 is coupled to the drive component 20, inparticular to the first drive part 71 of the drive component 20, by auni-directional clutch mechanism, for example a friction clutchmechanism. This clutch mechanism permits rotational movement of therotation member 21 with respect to the first drive part 71 when therotation member 21 rotates in the first direction with respect to thehousing part 17. The clutch mechanism prevents rotational movement ofthe rotation member 21 with respect to the first drive part 71, when therotation member rotates in the second direction with respect to thehousing part 17. Due to the coupling of the first and second drive parts71, 72, the first and second drive parts 71, 72 may thus followrotational movement of the rotation member 21 in the second directionwith respect to the housing part 17.

The first drive part 71 is arranged to engage the rotation member 21and, in particular, to abut the rotation member 21. The first drive part71 comprises first engagement means 22, e.g. a toothing. The first drivepart 71 comprises the toothing 22 at its proximal end. The rotatingmember 21 comprises first mating engagement means 23, e.g. a toothing.The rotation member 21 comprises the toothing 23 at its distal end whichfaces the first drive part 71. Toothing 22 comprises a plurality ofteeth 24. Toothing 23 comprises a plurality of teeth 25. Toothings 22and 23 are configured to mate with one another.

A respective tooth of teeth 24 and/or teeth 25 is ramp-shaped, inparticular along the azimuthal direction as seen from the rotation axis.The ramp of the respective tooth is limited in the angular direction bya steep end face of that tooth, i.e. a face of the tooth that runsparallel to the rotation axis or includes a smaller angle with therotation axis when projected on this axis than the ramp when projectedon this axis. The steep end face is followed by the ramp of the nexttooth.

The teeth 24 of the first drive part 71 may be circumferentiallydisposed on the first drive part 71, particularly at the end of thefirst drive part 71 which faces the rotation member 21. The teeth 25 maybe circumferentially disposed on the rotation member 21, particularly atthe end of the rotation member 21 which faces the first drive part 71.

When the steep end faces of two teeth abut and the rotation member 21 isrotated further on in the second direction, the steep sides stay inabutment and first drive part 71, thereby also the second drive part 72,follows the rotation of rotation member 21.

When the rotation member 21 rotates in the first direction, the ramp ofthe teeth—which ramps, in particular, run obliquely with respect to therotation axis—slide along each other and, in consequence, the rotationmember 21 rotates with respect to the first drive part 71 and thereby,also with respect to the second drive part 72.

The drive assembly 70 furthermore comprises a stop member 26. The drivecomponent 20 is arranged between the stop member 26 and the rotationmember 21. The stop member 26 is configured for preventing rotationalmovement of the drive component 20 in the first direction with respectto the housing part 17 during setting of a dose, i.e. when the rotationmember 21 rotates in the first direction. Thus, the rotation member 21may rotate in the first direction with respect to the housing part 17,whereas the drive component 20 and the stop member 26 are prevented fromrotating.

The stop member 26 is coupled to the second drive part 72 of the drivecomponent 20 by another uni-directional clutch mechanism, in particulara friction clutch mechanism. This clutch mechanism prevents rotationalmovement of the second drive part 72, and thus, the drive component 20,with respect to the stop member 26 when the rotation member 21 rotatesin the first direction with respect to the housing part 17. The clutchmechanism permits rotational movement of the second drive part 72, andthus, the drive component 20 with respect to the stop member 26, whenthe rotation member 21 rotates in the second direction with respect tothe housing part 17.

Thus, the rotation member 21 may rotate with respect to the drivecomponent 20 and the stop member 26 in the first direction duringsetting of a dose, wherein rotation of the drive component 20 isprevented by its interaction with the stop member 26. During delivery ofthe set dose, rotation member 21 as well as drive component 20 mayrotate with respect to the stop member 26 in the second direction.

The stop member 26 is arranged to abut and/or engage the drive component20 during setting of the dose and, preferably, during delivery of thedose. The stop member 26 comprises mating second engagement means 27,e.g. a toothing. The stop member 26 has the toothing 27 at one end whichfaces the second drive part 72 of the drive component 20, e.g. itsproximal end. The teeth are ramp-shaped with a steep side and a lesssteep ramp. The teeth may be azimuthally disposed along the stop member,in particular on the perimeter of the stop member.

The second drive part 72 comprises second engagement means 28, e.g. atoothing. The second drive part 72 has the toothing 28 at one end whichfaces the stop member 26, e.g. its distal end. Toothings 22 and 28 ofthe drive component 20 are oppositely disposed. Toothing 28 may beconfigured in accordance to toothing 21 of the rotation member, i.e. mayhave the same shape and the same angular position relative to therotation axis. Toothing 22 may be configured in accordance with toothing27 of the stop member, i.e. may have the same shape and the same angularposition relative to the rotation axis. Toothings 27 and 28, inparticular the steep sides of the teeth, do cooperate, e.g. abut, forpreventing rotation of the drive component 20 with respect to thehousing part 17 and, in particular, with respect to the stop member 26in the first direction.

The distance by which the first and second drive parts 71, 72 may beaxially displaced with respect to each other or the housing 13 duringdose setting and delivery operations may correspond to the maximum depthof a tooth of the respective toothing 22 or 28 of the drive component20. Alternatively, the distance may be larger than the maximum depth ofa tooth of the respective toothing.

The stop member 26 is secured against both rotational and axial movementwith respect to the housing part 17. The stop member 26 may be integralwith housing part 17 or an insert fixed to the housing part 17. Therotation member 21 may be secured against axial movement with respect tothe housing part 17.

The biasing member 73 of the drive component 20 is biased during drugdelivery operation of the drive assembly 70. The biasing member 73provides a force that tends to keep the second drive part 72 of thedrive component 20 in abutment with the stop member 26 and the firstdrive part 71 of the drive component in abutment with the rotationmember 21. In particular, the biasing member 73 forces the first andsecond drive parts 71, 72 apart in opposite axial direction towards therotation member 21 and the stop member 72, respectively.

The biasing member 73 keeps the second drive part 72 and the stop member26 in permanent mechanical contact, for example abutment, with eachother during setting and delivery of a dose of the drug. Additionally,the biasing member 73 keeps the first drive part 71 and the rotationmember 26 in permanent mechanical contact, for example abutment, witheach other during setting and delivery of a dose of the drug.

The drive assembly 70 furthermore comprises a support member 32. Supportmember 32 is expediently fixed against axial and rotational movementwith respect to the housing part 17 or integrated into housing part 17.Support member 32 may be a protrusion, for example a ring-likeprotrusion. Rotation member 21 extends through an opening in supportmember 32 and may comprise a radially outwardly protruding member 33,for example a flange portion. The protruding member 33 is expedientlyprovided for abutting support member 32, in particular the distal endside of support member 32. The support member 32 may provide for acounter force in the distal direction to the force which is exerted bythe biasing member 73 on the first drive part 71 and thereby on therotation member 21.

The stop member 26, which is secured against axial movement relative tothe housing part 17, provides a counter force in the proximal directionto the force exerted by the biasing member 73 on the second drive part72 and thereby on the stop member 26. Thereby, permanent abutment of therotation member 21 with the first drive part 71 and permanent abutmentof the stop member 26 with the second drive part 72 during setting anddelivery of drug is facilitated.

The drive assembly 70 furthermore comprises a dose member 34. The dosemember 34 may be dose part 16 or may be a part of the dose part 16 ofFIG. 1. The dose member 34 is movable with respect to the housing in theproximal direction for setting of a dose and for delivery of the dose.For example, the dose member 34 may be moved in the proximal directionwith respect to the housing part 17 during dose setting and in thedistal direction with respect to the housing part 17 during dosedelivery. The dose member 34 may engage the housing part 17 or,alternatively, another part of housing 13 (not explicitly shown). Thedose member 34 is preferably secured against rotational movement withrespect to the housing part 17. The dose member 34 may comprise a guidefeature 35, for example a guide lug or a guide slot, that engagesanother guide feature, for example a guide slot or a guide lug,respectively, that is provided in the housing part 17 or the housing 13.Thereby, rotational movement of the dose member 34 can be prevented.

The dose member 34 may be moved in the proximal direction and in thedistal direction with respect to rotation member 21. The dose member 34is preferably permanently coupled to rotation member 21 such thatmovement of the dose member 34, e.g. in the proximal direction withrespect to the housing part 17, for setting a dose of the drug isconverted into rotational movement of the rotation member 21 in thefirst direction and movement of the dose member 34, e.g. in the distaldirection with respect to the housing part 17, for delivering the doseis converted into rotational movement of the rotation member 21 in thesecond direction opposite to the first direction.

The rotation member 21 is provided with an outer thread 36. The thread36 is engaged with one of or a plurality of engagement members 42 of thedose member 34. The respective engagement member is arranged on theinside of the dose member 34. The respective engagement member may be athread or a part of a thread, for example. Thus, dose member 34 androtation member 21 are threadedly coupled, in particularly threadedlyengaged. The rotation member 21 is arranged inside the dose member 34.In other embodiments, the rotation member 21 may be arranged outside thedose member 34. The thread forms, in particular male and female threadforms, may be swapped, respectively.

The rotation member 21, the first drive part 71, the second drive part72, the stop member 26 and the dose member 34 comprise a respectivesleeve. The piston rod 12 is arranged to be driven and, in particular,is driven through the sleeves.

The drive component 20 and the piston rod 12 are configured such thatrotational movement of the drive component 20 with respect to thehousing 13 is converted into rotational movement of the piston rod 12with respect to the housing 13. In particular, at least one of the firstand second drive parts 71, 72 of the drive component 20 engages thepiston rod 12, for example are in splined engagement with the pistonrod. Preferably, both drive parts 71, 72 engage the piston rod. Thepiston rod 12 is displaceable with respect to the drive component 20along a displacement axis running along the rotation axis.

The piston rod 12 comprises an engagement track 37, preferably twooppositely disposed engagement tracks, on the outside. The (respective)engagement track 37 may interrupt thread 49. The (respective) engagementtrack 37 preferably linearly extends along the axis along which thepiston rod 12 is displaceable with respect to the housing 13 and, inparticular, with respect to the drive component 20.

At least one of the first and second drive parts 71, 72 comprise acorresponding engagement track running in an axial direction, configuredto be engaged with the engagement track 37 of the piston rod 12. Thecorresponding engagement track may be located at an inner surface of thesecond drive part 72 or the first drive part 71.

The piston rod 12 is threadedly coupled to the housing 13. The pistonrod 12 may be provided with an outer thread 49, for example. The pistonrod 12 may extend through and be engaged with a thread in an opening ofa housing part which may be formed integrally with housing part 17, maybe a housing part fixed thereto or may be a housing part securedseparately from housing part 17 to housing 13. In the depictedembodiment, the opening is formed in the stop member 26. Thereby, thestop member 26 is threadedly engaged with the piston rod 12.

Rotational movement of the drive component 20 with respect to thehousing 13 may thus be converted into rotational movement of the pistonrod 12 with respect to the housing 13 and the rotational movement of thepiston rod 12 is, on account of the threaded engagement of the pistonrod 12 and a part of or a part secured to the housing 13, converted intomovement of the piston rod 12 with respect to the housing 13 in thedistal direction.

At the distal end of the drive assembly 70, a resilient member 31 islocated. The resilient member 31 abuts a distal end face of the stopmember 26 and is compressed by a cartridge or a cartridge retainingmember when the cartridge is secured to the housing of the device.Thereby, the resilient member 31 pushes the cartridge towards the distalend of the cartridge retaining member.

In the following, operation of the present drive assembly 70 fordelivering drug from the cartridge 4 of FIG. 1 is described.

FIGS. 2 and 3 show the drive assembly 70 with indicated movements ofsome of its elements during a dose setting operation.

To set a dose, a user may manually move dose member 34 in the proximaldirection (arrow 43) with respect to the housing part 17. To do so, theuser may grip a dose knob and pull it in the proximal direction. Dosemember 34 moves proximally also with respect to the rotation member 21.Proximal movement of the rotation member 21 is prevented by supportmember 32 which abuts protruding member 33 of rotation member 21.Consequently, the proximal movement of dose member 34 with respect tothe housing part 17 is converted into rotational movement of therotation member 21 in the first direction (arrow 44) with respect to thehousing part 17, in particular on account of the threaded engagement ofdose member 34 and rotation member 21. Thus, the rotation member 21rotates in the first direction—counter-clockwise as seen from theproximal end of the rotation member 21—with respect to the housing 13.Rotation member 21 also rotates with respect to the drive component 20and to the stop member 26. The first and second drive parts 71, 72 ofdrive component 20 are prevented from rotating in the first direction byinteraction with the stop member 26, e.g. by interlocking of toothings27 and 28. As the piston rod 12 is coupled to the drive component 20 androtation in the first direction of the drive component 20 would causethe piston rod 12 to travel in the proximal direction, the piston rod 12is prevented from being driven in the proximal direction by interactionof stop member 26 and the second drive part 72 of drive component 20. Bypreventing the piston rod 12 from moving during dose setting doseaccuracy can be increased.

When the rotation member 21 rotates in the first direction, the ramps ofthe teeth of toothing 23 of rotation member 21 slide along the ramps ofthe teeth of toothing 22.

Thus, a tooth of the rotation member may index around the rotation axisuntil the tooth engages one of the next teeth of toothing 22 of thefirst drive part 71 of drive component 20. The teeth of rotation member21 slide along the ramps of the teeth of the first drive part 71 ofdrive component 20. During this movement, the first drive part 71 isdisplaced in distal direction along the rotation axis with respect topiston rod 12 and housing 13 by a distance determined by, preferablyequal to, the depth of a tooth of toothing 22, before a tooth oftoothing 23 (totally) disengages that tooth of toothing 22. Thereby, thefirst drive part 71 also moves towards the second drive part 72.Afterwards, the tooth of the rotation member 21 engages the next toothof toothing 22 and the force provided by biasing member 73 moves thefirst drive part 71 of drive component 20 back along the rotation axisinto the axial start position. An according movement of the first drivepart 71 of drive component 20 in the distal direction and back into theproximal direction is indicated by double arrow 45 in FIGS. 2 and 3.

A tooth of the rotation member 21 which engages the next tooth of thefirst drive part 71 of the drive component 20 may cause an audibleand/or tactile feedback to the user.

The drive assembly 70 is suitable for a fixed dose device or a variabledose device. In a fixed dose device, the size of the fixed dose of drugto be delivered is preferably determined by the pitch of the thread 49of the piston rod 12 and the number of teeth of the respective toothings22, 28, 23, 27 in the drive component 20, rotation member 21 and stopmember 26. In a variable dose device the increments in which a dose maybe varied by a user are preferably determined by the pitch of the thread49 of the piston rod 12 and the number of teeth of the respectivetoothings 22, 28, 23, 27 in the drive component 20, rotation member 21and stop member 26. The rotation member 21 may be rotated over more thanone tooth (dose increment) of the first drive part 71 of the drivecomponent 20 for a user-settable dose device and over one tooth only fora fixed dose device. The number of teeth and size of the angular rangeof a tooth in the first drive part 71 of drive component 20 over whichthe rotation member 21 rotates during dose setting determines the sizeof the dose which is actually delivered. The dose member 34 and therotation member 21 may be adapted to one another such that the rotationmember 21 may rotate only by one tooth for a fixed dose device and bymore than one tooth for a user-settable dose device.

FIGS. 4 and 5 show the drive assembly 70 with indicated movements ofsome of its elements during a dose delivery operation.

After the dose has been set, the dose part 16 and with it the dosemember 34 is moved (pushed) by the user in the distal direction withrespect to housing part 17 (arrow 46). Thus, the dose member 34 is movedin the distal direction with respect to the housing part 17. Therotation member 21 accordingly rotates in the second direction, which isopposite to the first direction, with respect to the housing (arrow 47).The first and second drive parts 71, 72 of drive component 20 followrotational movement of the rotation member 21 in the second direction.Rotational movement of the drive component 20 in the second direction isconverted into rotational movement of the piston rod 12 in the seconddirection, which movement, in turn, is converted into movement of thepiston rod 12 in the distal direction. Accordingly, the piston 10 ofFIG. 1 may be displaced in the distal direction with respect to thecartridge 4 and a dose of drug 5 is dispensed from the cartridge theamount of which corresponds to the previously set dose.

During dose delivery, toothings 22 of the first drive part 71 andtoothings 23 of the rotation member 21 interlock and ramps of the teethof toothing 28 of the second drive part 72 slide along ramps of theteeth of toothing 27 of stop member 26. This movement is similarly asdescribed above for the relative rotational movement of rotation memberand drive component with opposite rotation direction. The second part 72of drive component 20 is thereby displaced in the proximal directionwith respect to the stop member 26 by a distance corresponding to thedepth of a tooth of toothing 27 in stop member 26. Biasing member 73forces the second drive part 72 back into the axial starting position,when the next tooth of toothing 28 is engaged by the respective tooth oftoothing 27 (double arrow 48).

A tooth of second drive part 72 of the drive component 20 which engagesthe next tooth of the stop member 26 may cause an audible and/or tactilefeedback to the user.

REFERENCE NUMERALS

-   1 drug delivery device-   2 cartridge part-   3 drive part-   4 cartridge-   5 drug/drug-   6 outlet-   7 distal end of the device-   8 proximal end of the device-   9 membrane-   10 piston-   11 cartridge retaining member-   12 piston rod-   13 housing-   14 proximal end side of the cartridge part-   15 distal end side of the housing-   16 dose part-   17 housing part-   18 proximal end of housing part-   19 distal end of housing part-   20 drive component-   21 rotation member-   22 toothing of first part of drive component-   23 toothing of rotation member-   24 tooth of first part of drive component-   25 tooth of rotation member-   26 stop member-   27 toothing of stop member-   28 toothing of second part of drive component-   31 resilient member-   32 support member-   33 protruding member-   34 dose member-   35 guide feature-   36 thread-   37 engagement track-   38 engagement feature-   39 opening-   40 housing part-   41 dose knob-   42 engagement member-   43, 46 arrow indicating movement of dose member-   44, 47 arrow indicating movement of rotation member-   45, 48 arrow indicating axial displacement of first/second drive    parts-   49 thread-   70 drive assembly-   71 first drive part-   72 second drive part-   73 biasing member-   74 flange-   75 distal end face of first drive part-   76 retaining means-   77 guide slot-   78 stop face-   79 engagement feature

1-18. (canceled)
 19. A drive assembly for a drug delivery device, thedrive assembly comprising: a housing having a proximal end and a distalend, a rotation member being configured to be rotated in a firstdirection with respect to the housing during setting of a dose of a drugand to be rotated in a second direction with respect to the housingduring delivery of the dose, the second direction being opposite to thefirst direction, a drive component being configured to follow rotationalmovement of the rotation member in the second direction during deliveryof the dose, a stop member being configured to prevent rotationalmovement of the drive component in the first direction with respect tothe housing, wherein the drive component comprises a first drive partand a second drive part, coupled to each other such that relativerotational movement of the first and second drive parts is prevented andrelative axial movement is permitted, wherein the first drive part isconfigured for engagement with the rotation member, the stop memberbeing secured against both axial and rotational movements with respectto the housing and the stop member being configured to permit rotationalmovement of the drive component in the second direction with respect tothe housing.
 20. The drive assembly of claim 19, comprising a piston rodbeing configured to be displaced in the distal direction for deliveringa dose of a drug and being configured such that rotational movement ofthe drive component in the second direction is at least partiallyconverted into movement of the piston rod in the distal direction withrespect to the housing.
 21. The drive assembly of claim 19, wherein thedrive component comprises a biasing member for providing a force on atleast one of the first and second drive parts for keeping at least oneof the first and second drive parts in abutment with at least one of therotation member and the stop member.
 22. The drive assembly of claim 19,wherein at least one of the first and second drive parts comprises atoothing for engagement with at least one of the rotation member and thestop member.
 23. The drive assembly of claim 19, wherein the stop memberand the drive component are coupled to one another by a firstuni-directional friction clutch mechanism, which is configured toprevent relative rotational movement between the stop member and thedrive component in the first direction with respect to the housing andto permit relative rotational movement of the stop member and the drivecomponent in the second direction with respect to the housing.
 24. Adrive component for use in a drive assembly according to claim 19, thedrive component comprising a first drive part and a second drive part,coupled to each other such that relative rotational movement of thefirst and second drive parts is prevented and relative axial movement ispermitted, wherein the first drive part comprises first engagement meanswhich are configured for establishing a uni-directional friction clutchmechanism which is adapted and arranged to prevent rotational movementof the first drive part in a first direction and to permit rotationalmovement of the first drive part in a second direction with respect to amating first engagement means.
 25. A drug delivery device comprising atleast one of the drive assembly of claim 19, further comprising meansfor attaching a drug reservoir.